Researchers from the University of California, Los Angeles, have found a high fructose diet is not only bad for the body but also slows the brain and curbs memory and learning.
"Our findings illustrate that what you eat affects how you think," said Fernando Gomez-Pinilla, a professor of neurosurgery at the David Geffen School of Medicine at UCLA.
He said eating a sugary diet over the long term alters the brain's ability to learn and remember, but eating omega-3 fatty acids, such as flaxseed oil, can help counter that.
Researchers said this is the first study to reveal how fructose - specifically high-fructose corn syrup - influences the brain.
Scientists tested rats and fed them high-fructose corn syrup - commonly found in soft drinks, condiments, baby food and other processed fare - for six weeks in their drinking water. A second group drank the same solution but were also given flaxseed oil, rich in omega-3 fatty acids, and docosahexaenoic acid (DHA), which helps the body with memory and learning.
The rats were then tested in their ability to navigate a maze before and after they consumed their special diets.
They found the second group of rats navigated the maze much faster than the rats that didn't receive omega-3 fatty acids.
Researchers believe a high-sugar diet is to blame and insulin - which controls the body's blood sugar - may signal neurons to trigger reactions that disrupt learning and can cause memory loss, Gomez-Pinilla said.
He said the findings suggest consuming DHA regularly protects the brain against fructose's harmful effects.
"It's like saving money in the bank. You want to build a reserve for your brain to tap when it requires extra fuel to fight off future diseases."
The average Canadian consumed about 26 teaspoons of sugar per day in 2004, according to Statistics Canada.
The study was published Tuesday in the the Journal of Physiology.